The situation in north Kuwait oil-fields is used as an example to demonstrate the logic and the broad need for this practical invention. Similar situations may also take place in different parts of that country, in neighboring countries, and around the world. However, the invention is not restricted to use with such particular situations.
Mauddud is the largest reservoir in north Kuwait in terms of oil-in-place. It's a carbonate-based reservoir that extends over two oil-fields (Sabiriyah and Raudhatain). Improved Oil Recovery (IOR) for such fields by injecting seawater started in 2000. About 500,000 barrels per day (BPD) of seawater are currently injected. However, the location of the Seawater Treatment Plant (SWTP) and the way it is designed and operated attribute to inefficient performance along with a variety of oil wells' sulfate-related problems.
The future plan is to phase out seawater by 2020 and replace it with produced water as an IOR fluid. This may be due to the production of large amounts of produced water that ought to be managed. As such, a produced water treatment plant with a capacity of 950,000 BPD will be built. Nearly half of the plant's effluent water or more may be used for oil fields water injection operations (IOR) and the rest may be used for other applications and/or to be discharged off in disposal wells. The designed produced water treatment plant also forethoughts a different set of operating problems that will diminish its performance as well as impair oil wells.
To maintain oil production in Mauddud reservoir, the current and future IOR methods must be advanced to Enhanced Oil Recovery (EOR) methods. Several EOR methods were evaluated in bench and pilot setups. Miscible CO2-based Water-Alternating-Gas (WAG) is one of the evaluated EOR methods that provided the most effective overall oil sweep. However, it was dismissed because the availability and proximity of CO2 sources from the reservoir were perplexed at that time (2002), and the costs of conventional scrubbing methods and transferring CO2 from its sources (south Kuwait) to the reservoir (north Kuwait) deemed high. The applicability of WAG thus hinged on the availability of saline water and CO2 in sufficient quantities and acceptable qualities with the proximity of the reservoir.
The following presentation highlights the issues with the on-going seawater injection (IOR fluid), the projected produced water injection (IOR fluid) as well as the source and need of CO2 as a viable EOR fluid.